Newly generated rat IgG monoclonal antibodies (mAbs) recognize tags expressed as fusions with mouse Langerin (mLangerin). (A) Schematic view of different forms of recombinant mLangerin proteins. Cytosol, transmembrane (TM) and extracellular domain (ECD) of the mLangerin open reading frame (ORF) are indicated. A FLAG epitope tag and/or an E. coli OmpF derived flexible linker (OFL) sequences were fused to the N-terminus of the mLangerin ECD. (B) Different mLangerin constructs cloned into a CMV mammalian expression vector were transfected into 293T cells, followed by the Western blot analyses with newly generated rat IgG mAbs, i.e. L31 specific for the mLangerin ECD, and the new L2 and L5 MAbs specific for the sequence tags, and anti-FLAG (M2; mouse IgG mAb from Sigma-Aldrich) and anti-beta-actin.